FCC Adopts New Rules on RF Safety
The FCC recently voted to change its rules on how to best protect the general public and trained workers from the health risks associated with radiofrequency (RF) emissions. The FCC decided not to change its long-standing RF exposure limits, finding that there was an insufficient scientific record to change the current levels of protection. However, the FCC adopted new rules for RF exposure in three areas: (1) broad exemptions from RF evaluation for certain types of radio transmissions; (2) calculations that should be used if a general exemption does not apply; and (3) mitigation procedures that should be used to ensure that the general public and RF-trained workers are not exposed to RF levels in excess of the FCC’s exposure limits. The FCC is also inviting comment on:
I. New RF Safety Rules
A. Exemptions from RF Evaluation
To simplify its current exemptions from RF evaluations the FCC has adopted new exemptions that will be applied to all types of transmitting devices. The new exemptions are broadly grouped into three classes:
- 1. Extremely low-power devices that transmit at no more than 1 milliwatt will be exempt.
- 2. Low-power devices with antennas that will be used between 0.5 and 40 cm of the body will be evaluated under formulas that take into account frequency, power and separation distance between the antenna and the body.
- 3. All other transmitters will be reviewed against a table of Maximum Permissible Exposures (MPEs) for any frequency between 300 kHz and 100 GHz.
The FCC will issue further technical guidance on how to evaluate non-exempt devices.
B. Mitigation Measures to Ensure Compliance
The basic concept of mitigation is to ensure that individuals are kept out of areas with RF levels that exceed the FCC’s exposure limits unless they are specially trained in RF safety.
The FCC has adopted more precise language on “transient exposure” so that an untrained person may transit through an area of higher RF radiation if the exposure does not exceed the general population limit when exposure levels are averaged over a time interval of 30 minutes. The area must have access controls and appropriate signage, and the individual must be escorted by RF-trained personnel to ensure compliance. Employees and contractors (such as utility workers, roofers, HVAC technicians, etc.) who must perform any task or stop in an area that exceeds the general population limits may not be considered “transient” but must be trained in RF safety.
The FCC will require licensees to use warning signs when a location will have RF levels above the limit for the general public. The FCC will also allow use of indicators (chains, railings, paint and diagrams) if other positive access controls (e.g., a locked door to the rooftop) are in place to restrict access to persons who are RF trained. The FCC adopted four categories for RF safety actions:
- Category 1: Locations where RF energy is not in excess of the general population limit. Signage is not required but if used must show a green “INFORMATION” heading.
- Category 2: Locations where the continuous exposure limit for the general population is exceeded but not for RF-trained personnel. These locations must have positive access controls and signs with the word “NOTICE” in blue color.
- Category 3: Locations where the exposure limit for occupational (RF-trained) personnel would be exceeded by no more than a factor of ten. The FCC will require signs with the word “CAUTION” in yellow color, and controls or indicators (chains, railings, contrasting paint, diagrams, etc.) in addition to positive access control.
- Category 4: Locations where the exposure limit for RF-trained personnel would be exceeded by more than a factor of ten or where there is a possibility for serious contact injury. “WARNING” signs in orange color are required, and “DANGER” signs in red color are required where immediate and serious injury will occur on contact, in addition to positive access control.
Signs must readily viewable at a minimum distance of five feet from the boundary at which the limits are exceeded. Signs must include a point of contact, the RF energy advisory symbol, an explanation of the RF source, and how to comply with the exposure limits.
Persons who will be working in controlled (high RF) areas must be “fully aware” of the potential for exposure and must be able to control their exposure. Workers must receive training on how to control their exposure and must be allowed to reduce or avoid exposure by wearing personal protective equipment or reducing the time spent in high RF areas. Posting information on signage at an access door is not sufficient to constitute “training.”
If a new licensee at a transmit site causes the site to go out of compliance the new entrant is responsible for evaluating the site to ensure compliance, but all licensees share responsibility for any modification or remediation necessary to bring the site into compliance. To avoid public confusion, the FCC will preempt any state or local requirements regarding RF signage or barriers that go beyond what is required by the FCC.
C. Transition Periods
The FCC will allow two years from the effective date of the new rules for licensees to determine if new evaluations are required, to perform them if necessary, and to comply with the new mitigation measures. Nevertheless, the FCC encourages licensees to utilize the new signage and other guidance as soon as possible.
II. Notice of Proposed Rulemaking
The FCC also opened a new rulemaking proceeding to consider whether the FCC should expand its rules to new technologies; for example, (1) whether to expand the range of frequencies to which the RF exposure limits will apply (currently limited to 100 kHz to 100 GHz); (2) the conditions and methods on which exposure limits are averaged, in both time and area, during evaluations; and (3) how to address issues related to wireless power transfer (WPT) devices that emit RF energy for the transfer of power, such as to charge or power devices within a room or for higher power devices that could charge batteries in a vehicle.
If your company is interested in learning more about the new RF rules or how you can ensure compliance, please contact LB3’s Jeff Sheldon.